Local radiation causes significant declines in lymphocyte counts. The mechanism for this decline as well as the types of lymphocytes making up this decline are presently unknown. In animals, beta-carotene attenuates this decline. The purpose of the present study is to characterize the T cell subsets that are declining in response to local radiation as well as examine the effect of beta-carotene to block this effect. This study is double-blinded. COMPUTER ONLY.